# a = input('请输入一个数：')
# b = input('请输入一个数：')
# c = input('请输入一个数：')
# d = input('请输入一个数：')
#
# a = float(a)
# b = float(b)
# c = float(c)
# d = float(d)
#
# avg = (a + b + c + d) / 4
#
# print(f'平均数为：{avg}')

# a = 0
# a += 1
# print(a)